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Opportunities to Influence ENERGY STAR® 6.0 Skylight Criteria Closing Fast

Post Time:Feb 01,2013Classify:Industry NewsView:73

The Environmental Protection Agency (EPA) issued Draft 2 of the proposed ENERGY STAR 6.0 criteria for windows, doors and skylights on January 7, 2013. The current comment period on Draft 2 expires February 8, 2013.  These comments will be reviewed through March and final program requirements will be published in April.

While the thermal performance criteria proposed in Draft 2 are largely unchanged from Draft 1, EPA has made several revisions based on stakeholder comments. These changes focused primarily on doors with lites, U-factor versus solar heat gain coefficient (SHGC) tradeoffs for windows in Climate Zone 1 and clarifications to requirements for installation instructions and air leakage test methods.

Regarding the implementation date, EPA noted that it “has already pushed back the estimated implementation date for the Version 6.0 criteria,” the EPA denied industry requests to extend the deadline to January 1, 2015. The date remains as January 1, 2014, and EPA “does not anticipate any further delays.”

With specific regard to skylights, Draft 2 and EPA’s responses to Draft 1 commentary were as follows:

Skylight Thermal Performance Criteria Unchanged
AAMA submitted recommended skylight U-factor and SHGC levels based on production costs versus homeowners anticipated return on investment in energy savings. These, however, were rejected and the criteria remain the same as in Draft 1 per the following table:

Skylight Criteria

AAMA had noted that the 2012 IECC sets prescriptive skylight SHGC at 0.30, where windows stand at 0.25, and EPA had not justified this difference. Especially in the Northern Climate Zone, reducing SHGC can actually result in poorer energy performance.

But EPA made no change in the SHGC criteria, citing its “concern about heat gain and possible consumer discomfort, especially in summer months, because skylights receive more direct sun than windows.” Specifically, in response to AAMA comments regarding SHGC values for skylights, the agency said:

  • “EPA expects [emphasis added] skylights to have higher SHGC due to the direct sun they receive.
  • “EPA seeks to exceed [emphasis added] the 2012 IECC SHGC requirements set for skylights.
  • “EPA seeks to set criteria that can deliver energy savings in typical residential skylight applications. It is not clear from the stakeholder’s comments in what applications lower SHGC does not result in better energy performance in the two ENERGY STAR southern zones or at what frequency these applications occur.”

Skylight Market and Availability Analyses Explained
AAMA recommended that the EPA use a similar methodology for analyzing the market for skylight products as it did for analyzing the window market in determining the latest set of criteria. Specifically, EPA should justify the “broadly available for sale” assumptions used, as was done for windows.

In response, EPA notes that a correlation study was not performed for skylights because data on products available for sale was collected from all skylight manufacturers that had such data available on their websites, not a subset of manufacturers as was done for windows.

Using the NFRC certified products directory (CPD) data as a determinant of the number of units available was questioned. EPA responded that it “did not use the CPD to estimate the number of products available for sale; instead it used the CPD only to determine what products could feasibly be manufactured.”

Payback Period Estimates Remain Questionable; More Cost Info Needed
AAMA’s comments to Draft 1 observed that payback calculations indicate the proposed criteria are not economically justified, especially in the three southerly climate zones.

But, EPA “sees the low energy savings as a greater contributor to the longer payback periods for skylights. A small shift in the criteria would have resulted in even smaller energy savings for these products.”

AAMA had further noted that the recoupment costs within the “Calculation of Simple Payback” table are based on recovery upon the eventual sale of the home. Unless clarified, this data will mislead homeowners/purchasers. Many stakeholders questioned the payback period for investing in ENERGY STAR products as calculated by EPA. Generally, periods falling in the range of five to 10 years were considered acceptable while—especially in the Northern Zone—payback was calculated at 11 to 13 years by the EPA. Another stakeholder commented that the cost of product redesign needed to meet maximum SHGC = 0.25 criteria in the North-Central Zone would result in a payback period of 38.9 years.

In response, EPA said that it “understands that there are many different viewpoints on what constitutes a ‘reasonable’ payback period. Due to the long life of fenestration products, EPA believes that payback within the lifetime of the product represents a reasonable payback period. In the excessive case cited, EPA rejoined that it had calculated a payback of 13-20 years. As a national program, ENERGY STAR must make some basic assumptions to evaluate and set criteria.” However, “EPA welcomes any additional cost data that manufacturers would like to volunteer.”

EPA to Skylight Manufacturers: “Prove It”
Stakeholders complained that data sets for determining cost-effectiveness were more limited for skylights than for windows. EPA responded that it had “evaluated all cost data volunteered by manufacturers. No other cost data sets were available at the time and no additional data sets have been volunteered. If manufacturers wish to submit additional cost data, EPA would welcome the additional data.

TDD U-Factor Testing Still an Open Issue
A stakeholder pointed out that modifications to “the only available U-factor test apparatus” have resulted in 60 percent to 90 percent increases in as-tested U-factor ratings. SHGC ratings will likely be affected as well. As a result, there are products with extremely low U-factor ratings on the CPD, but based on product design and testing, dual-pane diffuser designs should not be able to achieve a U-factor below 0.50. Triple-pane diffusers may achieve a U-factor below 0.50, but any reported U-factors below 0.40 should be suspect. The proposed criteria would prevent any tubular daylight devices (TDDs) from obtaining ENERGY STAR qualification.

EPA responded that it appreciates hearing about this issue and “will monitor developments as manufacturers work to resolve the issue with NFRC. Before it can consider revising the specification, EPA will need to collect additional data.”

TDD Classification Unchanged; More Data Needed
AAMA recommended that EPA consider removing TDDs from the skylight criteria category, especially in view of the questioned U-factor testing data.

This issue is still open, as EPA’s response was that “the classification of TDDs as a subtype of skylights has not changed” and that it “will not be making any revisions to the specification to account for the changes in TDD test results until additional information is available.” EPA will continue to monitor developments. If it becomes necessary, EPA may reconsider providing a separate category for TDDs, “but at this time there is not enough data or information regarding TDD testing issue to make a decision. EPA … notes that ENERGY STAR sets specifications based on energy performance criteria, not design or technology used.”

D&R International has recently been in contact with at least one AAMA member/TDD manufacturer, indicating they had received the data they were waiting for and were beginning their analysis for the EPA.

Penalizing Curb-Mounted Skylights; Back in the Industry’s Court
Stakeholders commented that the proposed Draft 1 specification dramatically and disproportionately affects curb-mount products. EPA’s response was that “Cost-effectiveness, broad availability and ability to qualify are evaluated at the product level, not the product subtype level. EPA realizes that many curb-mounted skylights may no longer qualify…but the performance of these products is highly dependent on the performance of the curbs. EPA suggests that the industry work to improve curb performance and the corresponding test procedures.”

Market Conditions
AAMA believes that for the ENERGY STAR program to maintain its brand recognition and continue to move products to be more energy efficient, new criteria must be both challenging and attainable. If manufacturers or homeowners are burdened with costs that neither can afford, the quest for energy efficiency will suffer rather than thrive.

One More Opportunity
Note that opportunities still exist to influence the final v6.0 criteria, specifically in areas noted above where EPA has left the door open for more input—i.e., NAFS air leakage certification label examples, payback period cost data and TDD test data.

Written comments should be submitted to EPA at
EPA will post all comments to the ENERGY STAR Product Development website, unless the submitter requests otherwise. Supporting data and documentation for all comments should be submitted where relevant. If submissions contain confidential information, this should be clearly and prominently indicated at the top of the document(s).

Interested parties can follow stakeholder comments and EPA’s progress in revising the ENERGY STAR Window, Door, and Skylight specification. To be added to the stakeholder list, contact

Source: http://www.glassonweb.com/news/index/18215/Author: